HR-HPV type viral infections, if left untreated, can convert normal cervical lining to cervical intraepithelial neoplasia (CIN). With a good immune response, the hyperplasia regresses and no carcinoma develops. This regression ocassionally occurs with CIN 2, but rarely occurs with CIN 3. If the CIN does not regress, high-grade squamous intraepithelial lesions (HSIL) develop. HSIL may progress to invasive carcinoma, typically in older individuals.
